workflow: mkosi: Publish qcow2 with oras

Publish the podvm qcow2 files with oras

Signed-off-by: stevenhorsman <steven@uk.ibm.com>

.github/workflows/podvm_mkosi.yaml

@@ -292,6 +292,37 @@ jobs:
           REGISTRY: ${{ inputs.registry }}
           PODVM_TAG: ${{ steps.image_tag.outputs.image_tag }}
 
+      - name: Upload the qcow2 with oras
+        id: publish
+        working-directory: src/cloud-api-adaptor/podvm-mkosi
+        run: |
+          mkdir oras
+          cd oras
+          cp build/podvm-*.qcow2 .
+          image=${{ inputs.registry }}/podvm-generic-fedora
+          if [ "${{inputs.debug}}" = "true" ]; then
+            image=${image}-debug
+          fi
+          tag=${{ steps.image_tag.outputs.image_tag }}
+          arch_tag=${tag}_-${{ matrix.platforms.arch }}
+          oras push "${image}:${arch_tag}" podvm-*.qcow2
+          # We need to create the platform annotations with docker, since oras 1.2 doesn't support
+          # pushing with platform yet.
+          docker manifest create "${image}:${tag}" --amend "${image}:${arch_tag}"
+          docker manifest annotate --arch "${{ matrix.platforms.arch }}" --os linux "${image}:${tag}" "${image}:${arch_tag}"
+          docker manifest push "${image}:${tag}"
+          # add image and digest to output for attestation
+          echo "image=${image}" >> "$GITHUB_OUTPUT"
+          digest="$(oras manifest fetch "${image}:${arch_tag}" --descriptor | jq -r .digest)"
+          echo "digest=${digest}" >> "$GITHUB_OUTPUT"
+
+      - uses: actions/attest-build-provenance@v1
+        with:
+          subject-name: ${{ steps.publish.outputs.image }}
+          subject-digest: ${{ steps.publish.outputs.digest }}
+          push-to-registry: true
+
+
       - name: Clean up some space for the docker provider build
         working-directory: src/cloud-api-adaptor/podvm-mkosi
         run: |